Many data distribution applications (e.g., stock price broadcasts) and multimedia applications require network multicasting or multipoint communication. Any layer(s) of the protocol stack can provide this service. In particular, application layer, transport layer, network layer, datalink layer, and/or physical layer can provide multipoint communication. Due to recent interest in multimedia applications, multipoint communication has become an active topic for protocol designers. A number of networking standards organizations have been working on designing multicast protocols. In this talk, efforts at IEEE, IETF, and ATM Forum will be explained.